Effect of Yoga on Oxidative Stress in Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis

Diabetes mellitus has a significant impact on public health. Oxidative stress plays a major role in the pathophysiology of Type 2 Diabetes Mellitus (T2DM), leading to various complications of T2DM. Yoga is being widely used in the management of T2DM. The primary objective of this systematic review and meta-analysis is to understand the effects of yoga on oxidative stress parameters among adult patients diagnosed with T2DM.

Electronic databases such as PubMed, Scopus, Cochrane Library and Science Direct from start of the study till March 2020 were searched to obtain eligible studies. Study designs of all nature were included (except case studies and reviews). The primary outcome was Malondialdehyde (MDA) and secondary outcomes included fasting plasma glucose, HbA1C and Superoxide Dismutase (SOD) levels.

A total of four trials with a total of 440 patients met the inclusion criteria. The results of meta-analysis indicated that yoga significantly reduced MDA (SMD: -1.4; 95% CI -2.66 to -0.13; P = 0.03; I2 = 97%), fasting plasma glucose levels (SMD: -1.87: 95% CI -3.83 to -0.09; P = 0.06; I2= 99%), and HbA1c (SMD: -1.92; 95% CI - 3.03 to -0.81; P = 0.0007; I2 = 92%) in patients with T2DM. No such effect was found for SOD (SMD: -1.01; 95% CI -4.41 to 2.38; P = 0.56; I2= 99%).

The available evidence suggests that yoga reduces MDA, fasting plasma glucose and HbA1C, and thus would be beneficial in the management of T2DM as a complementary therapy. However, considering the limited number of studies and its heterogeneity, further robust studies are necessary to strengthen our findings and investigate the long-term benefits of yoga.